For value determination, an established guide on the forum is referenced that all collectors use. High-quality 744-N sets can, in intact condition, achieve four-digit amounts; a personal engraving, however, reduces the value clearly. Subsequent removal of an engraving is theoretically possible (by filling with gold) but in practice barely feasible, since the surface cannot be restored without visible traces. Before sale a professional overhaul is recommended, since long-unused writing instruments often show sealing and mechanism problems.